This invention relates generally to devices for implementing a ground connection between an electrical meter box and a common ground point. More particularly, the present invention relates generally to clamp devices which mount to an electrical meter box and connect via a flexible conductor with a common ground point.
A number of various types of devices have been employed for connecting a ground wire with an electrical meter box. Most conventional devices employ clamp assemblies of various forms. In applications to which the present invention relates, the connecting devices are ordinarily clamped onto the exterior of the electrical meter box which is mounted on the wall of a building.
A number of conventional designs are configured to mount rigidly or semi-rigidly onto the electrical meter box. For such designs, damage to the electrical meter box can occur when the clamping force is applied to the electrical meter box. For example, it is not uncommon for the electrical meter box to be bent or twisted when the clamping force is applied.
In another known design, the device clamps onto a corner of the electrical meter box. A lower flange of the device engages a bottom skirt of the electrical meter box top cover. A bolt threadably disposed through a top plate of the device engages the electrical meter box top cover. Applying a torque to the bolt causes the device to be clamped to the electrical meter box. Such devices may not provide an adequate electrical connection with the electrical meter box.
A ground clamp disclosed in U.S. Pat. No. 6,329,592 includes a U-shaped clamp member having first and second legs which form a slot. A pair of openings in the first leg form a center segment disposed between two fingers. The edge portion of the meter box enclosure is resiliently clamped within the slot between the fingers and the second leg. The center segment includes a threaded socket. A bolt member has a stud portion and a bolt head portion, the stud portion including a threaded segment disposed proximate the distal end and an unthreaded shaft segment disposed intermediate the threaded segment and the bolt head portion. At least one protrusion extends axially from the distal end of the bolt member to a sharp edge. The stud portion is mounted in the socket of the clamp member such that the shaft segment is positioned in the threaded portion of the socket and the threaded segment is positioned within the slot when the sharp edge of the protrusion contacts the exterior surface of the edge portion received within the slot. The sharp edge of the protrusion removes the corrosion inhibiting coating from the exterior surface of the edge portion to electrically connect the meter box to the clamp without deforming the meter box enclosure upon rotation of the bolt member. However, a hammer or similar tool is usually required to insert the second leg of the clamp member between the bottom skirt of the meter box top cover and the side or front panel of the meter box.